An object with a mass of 8 kg is acted on by two forces. The first is F_1= < -9 N , 2 N> and the second is F_2 = < 6 N, -3 N>. What is the object's rate and direction of acceleration?

1 Answer
Jan 31, 2018

The object's rate of acceleration is =0.40ms^-2 in the direction 198.4^@ anticlockwise from the x-axis.

Explanation:

The resultant force is

vecF=vecF_1+vecF_2 = <-9,2> + <6,-3>

= <-3, -1>

The mass of the object is m=8kg

According to Newton's Second Law

vecF=mveca

The acceleration is

veca=1/mvecF=1/8* <-3, -1> = <-3/8, -1/8>

The rate of acceleration is

||veca||= ||<-3/8, -1/8>|| = sqrt((-3/8)^2+(-1/8)^2)

=sqrt(9/64+1/64)

=1/8sqrt10

=0.40ms^-2

The direction is

theta=180^@+arctan(1/3)=180+18.4=198.4^@ anticlockwise from the x-axis.